When Attorney General Andrew M. Cuomo wanted to meet certain members of the hedge fund crowd, seeking donors for his all-but-certain run for governor, what he heard was this: Talk to Joe.

That would be Joe Williams, executive director of a political action committee that advances what has become a favorite cause of many of the wealthy founders of New York hedge funds: charter schools...

Hedge fund executives are thus emerging as perhaps the first significant political counterweight to the powerful teachers unions, which strongly oppose expanding charter schools in their current form....